Huge FPS Drops Since 5.0

Ok, so since 5.0 whenever I start WoW it runs normally, no problems at all. However after playing for even a few minutes if I decide to go to places like Orgrimmar, or Paw'don Village I end up watching a slideshow for 5-10 minutes. Nothing is really responsive and the game only updates once every few seconds. This can also start affecting all zones, when you try to turn it freezes and takes several seconds to update again. I know my computer can handle it because if I start in Orgrimmar/SW/Jade Forest I can get 40+ FPS all the time, it seems to happen most often if I have to go through a load screen and once it starts the only way to fix it is to log out wait a while and try again.

Many people have attributed this to a memory leak however I decided to see if I could find a way to resolve these issues as the game is becoming almost unplayable. (Getting ganked when you can see it coming but only being able to respond at the speed of a power point presentation when you try and turn to face your attacker is not fun) I never really noticed any RAM issues, WoW tended to stay <1GB so I do not believe this is the case. However I did notice something rather strange. When these spikes happen my CPU goes down to 0-1% usage, and shoots back up to 60-65% when it updates then back to 1% in an ongoing cycle until it eventually decides that its going to stay at a steady 25-30%. This happens every single time there is a spike without fail and is particularly noticeable when teleporting to SW/Org/Jade Forest, and most highly populated areas, as well as once the game has been running for a while, and you try to turn quickly.

GPU memory and load stays pretty much the same all the time, of course it gets slightly higher when it has to load more characters, (5-10% difference between Org Valley of Strength and the top of a mountain in The Barrens looking at the sky) but it does not have an issue unless I have to go back to a populated area using a load screen. Basically If I log on in Orgrimmar, I get 40+ FPS, I can fly around and whatnot with no noticeable FPS drops. If I take a zepplin to say Tirisfal , and back my FPS is now .0000001 until WoW decides it can use more than 1% of the CPU and at this point even after it settles, turning or moving can cause it to happen again.

I am not sure what is causing this, but not using the CPU properly after load screens cannot be an intended feature. If anyone else has insight or thoughts on this it would be greatly appreciated, I will also be submitting this on the actual forums, however the website seems to be down at the moment.